Display device

ABSTRACT

A display device is provided including a first substrate comprising a resin material provided with a plurality region provided with a plurality of pixels including a display device, and a second substrate provided facing the first substrate and installed with the pixel region, wherein an outer periphery side surface of the first substrate having a taper shape and including a barrier layer covering an upper layer, lower layer and the outer periphery side surface of the first substrate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2014-071652, filed on Mar. 312014, the entire contents of which are incorporated herein by reference.

FIELD

The present invention is related to a display device and one embodimentof the disclosed invention is related to a sealing structure of a panelin the display device.

BACKGROUND

An organic electroluminescence device (referred to below as “organic ELdevice”) is provided with an organic electroluminescence layer (referredto below as “organic EL layer”) between an anode and cathode. Althoughthe organic EL device emits light according to the amount of currentflowing in the device, it is known that water or oxygen badly affectsthe organic EL device which degrades light emitting characteristics.

As a result, an organic electroluminescence display device (belowreferred to as “organic EL display device”) formed with pixels using anorganic EL device is usually provided with a structure in which a pixelregion is sealed with a sealing material. Although various structureshave been examined for the sealing structure of an organic EL displaydevice, for example, a structure is known in which a sealing substrateis bonded facing a substrate provided with a pixel using an organic ELdevice.

The structure in which a substrate formed with an organic EL device isbonded with sealing substrate is similar to a liquid crystal displaydevice in which a liquid crystal material is held between a pair ofsubstrates. However, because an organic EL display device an image usingthe light emitted by an organic EL device, a back light is not requiredunlike in a liquid crystal display device and in principle it ispossible to achieve a thin display panel. Furthermore, it is thoughtthat it is possible to also realize a sheet shaped display panel (sheetdisplay) by applying a resin film to a substrate formed with a device ora sealing substrate.

Even in the vase where a resin film is used as a substrate in an organicEL display device, a sealing structure is necessary in order to preventdegradation due to the effects of water on the organic EL device.Generally, a resin film has the property to allow water to pass throughand also includes the property whereby water is easily included and onceincluded is reradiated.

As a result, arranging a barrier layer on a resin film used as asubstrate in an organic EL display device in order to prevent theinfiltration of water has been examined. For example, in Japanese LaidOpen Patent No. 2011-227369, an image display device is disclosedprovided with a first substrate comprised from a curved transparentsubstrate and a resin film formed with a thin film transistor adhered toan upper layer of the first substrate, wherein the barrier layer iscomprised form an inorganic layer which covers the surface, rear surfaceand side surface of the resin film.

However, since the structure of the end surface of the resin film hasnot been considered in the display device described in the patentdocument 1, the problem whereby barrier properties at the end surfaceare insufficient still remains. In addition, because a process forforming a double resin film layer is necessary, an increase in componentcosts and manufacturing costs is considered a problem.

When the end surface of a resin film is cut perpendicularly, it ispossible that the end surface is not sufficiently covered by a barrierlayer. In the case where a barrier layer is a thin film comprised froman inorganic material such as a silicon oxide layer or silicon nitridelayer, the barrier layer is formed using a sputtering method or plasmaCVD method. However, this type of thin film formed from an inorganicmaterial is not always formed at a uniform thickness at the end surfaceperpendicular with the surface of the resin film.

In the case where the film thickness of the barrier layer at the endsurface of the resin film is insufficient, water or oxygen enters thedevice from that part. On the other hand, when attempting to make thefilm thickness of the barrier layer at the end surface of the resin filmthicker, the film thickness of the surface side the resin filmincreases, the flexibility of the film is lost and there is a dangerthat cracks appear in the barrier film when the resin film is bent.

Therefore, one embodiment of the present invention aims to provide adisplay device with a high level of reliability which prevents theinfiltration of water or oxygen from the end surface of a substrate in adisplay device which uses a resin film as the substrate.

SUMMARY

According to one embodiment of the present invention, a display deviceis provided including a first substrate comprising a resin materialprovided with a plurality region provided with a plurality of pixelsincluding a display device, and a second substrate provided facing thefirst substrate and installed with the pixel region, an outer peripheryside surface of the first substrate having a taper shape and including abarrier layer covering an upper layer, lower layer and the outerperiphery side surface of the first substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a planar diagram showing the structure of a display devicerelated to one embodiment of the present invention;

FIG. 2 is a planar diagram explaining the manufacture process of adisplay device related to one embodiment of the present invention;

FIG. 3A˜3D are cross-sectional diagrams explaining the manufactureprocess of a display device related to one embodiment of the presentinvention;

FIG. 4A˜4C are cross-sectional diagrams explaining the manufactureprocess of a display device related to one embodiment of the presentinvention;

FIG. 5A˜5C are cross-sectional diagrams explaining the manufactureprocess of a display device related to one embodiment of the presentinvention;

FIG. 6 is a cross-sectional diagram explaining the structure of adisplay device related to one embodiment of the present invention;

FIG. 7 is a cross-sectional diagram explaining the structure of adisplay device related to one embodiment of the present invention;

FIG. 8 is a cross-sectional diagram explaining the structure of adisplay device related to one embodiment of the present invention; and

FIG. 9 is a cross-sectional diagram explaining the structure of adisplay device related to one embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The embodiments of the present invention are explained below whilereferring to the diagrams. However, the present invention can berealized by various different forms and should not be interpreted asbeing limited to the contents described in the embodiments exemplifiedbelow. In addition, although the width, thickness and shape of each partare sometimes displayed schematically compared to the actual form in thediagrams in order to clarify the explanation, these are just examplesand should not limit the interpretation of the present invention. Inaddition, in the present specification and diagrams, the same symbolsare applied to the same elements described previously in the diagramsand a detailed explanation is sometimes omitted where appropriate.

In the present specification, there is no particular limitation in thecase where certain parts or regions are [above (or below)] other partsor regions, and this applies not only when directly above (or directlybelow) other parts or regions but also includes cases when in an upper(or lower) direction of other parts or regions, that is, otherstructural components may be included between the other upper (or lower)parts or regions.

First Embodiment Display Device

The structure and manufacturing method of the display device relayed toone embodiment of the present invention is explained while referring tothe diagrams. In the present embodiment, a display device which forms apixel is explained in the case where is an organic EL device as one formof a display device 100.

FIG. 1 shows the structure of a display device 100 related to oneembodiment of the present invention. The display device 100 is providedwith a pixel region 108 in which a plurality of pixel are aligned in afirst substrate 102. A second substrate 104 which is provided facing thefirst substrate 102 is provided so as to seal the pixel region 108. Inthe present embodiment, the first substrate 102 and second substrate 104is preferred to be formed using a resin material, for example, a highmolecular compound including an imide bond can be used and a polyimideresin can be suitably used.

The display device 100 may be provided with a first drive circuit whichprovides a scanning signal to the pixel region 108 and a second drivecircuit 112 which provides a video signal, and the first substrate 102may also be provided with an input terminal 114.

An end surface region 105 which is a region which includes a substratesurface in an outer periphery end part of the first substrate 102 has atape shape. This taper shape has a thickness which gradually increasestowards an inner region (towards the surface provided with the pixelregion 108) from an outer end part of the first substrate 102. The pixelregion 108 provided above the first substrate 102 is provided further tothe interior than the end surface region 105.

The first substrate 102 is provided with a cover film which preventswater (or water vapor) from attaching or entering the first substrate102 including the end surface region 105. In the explanation below, thiscover film is referred to as a “barrier film” or “barrier layer”. Thebarrier layer which covers the first substrate 102 is formed using aninorganic material. It is preferred that a material having insulationproperties is used as the inorganic material and the barrier layer canbe formed using one or a plurality of insulation films. In addition, inthe case where the barrier layer is formed using a plurality of coverfilms, a metal film may also be included as one type of cover film.

<Manufacturing Process>

Next, the display device 100 is explained in detail while referring tothe manufacturing process. FIG. 2 is a planar diagram which shows thearrangement of a plurality of first substrates 102 provided with thepixel region 108. FIG. 2 shows one example of multi-patterning aplurality of display panels from a large area mother glass substrate. Inaddition, the cross-sectional structure along the cut line A-D shown inFIG. 2A is shown in FIG. 3A˜3D and FIG. 4A˜4C. Furthermore, FIG. 3A˜3Dand FIG. 4A˜4C are diagrams explaining the manufacturing process of thedisplay device shown in the present embodiment.

FIG. 2 shows an example whereby a plurality of substrates 102 areprovided above a support substrate 116. The support substrate 116 isshown in the case of a mother glass substrate and shows multi-patterninga plurality of display panels.

The pixel region 108 is provided in the first substrate 102. Inaddition, as is shown in the diagram, a first drive circuit 110 andsecond drive circuit 112 may also be provided in addition to the inputterminal 114. A second substrate 104 which seals the pixel region 108 isprovided above the first substrate 102 and lastly the display device iscompleted after the first substrate 102 is peeled from the supportsubstrate 116. This manufacturing process is explained below whilereferring to FIG. 3A˜3D and FIG. 4A˜4C.

FIG. 3A shows the stage of forming a first barrier layer 122 and resinlayer 120 on roughly the entire surface above the support substrate 116.The first barrier layer 122 is formed using an inorganic material. Forexample, a thin film using silicon nitride, silicon oxide, siliconoxynitride or aluminum oxide is formed using a sputtering method orplasma CVD method. Although there is no limitation to the thickness ofthe first barrier layer 122, for example, 50 nanometers or more and 1000nanometers or less and 100 nan-meters or more and 500 nanometers of lessis preferred. It is possible to prevent the transmission of water (orwater vapor) by setting the film thickness of the first barrier layer122 within this range.

Furthermore, in order for the first barrier layer 122 to be peeled fromthe support substrate 116 together with the first substrate 102, it ispreferred that the first barrier layer 122 be a cover film with a weakadhesion compared to the support substrate 116. That is, the firstbarrier layer is preferred to be able to be peeled from the firstsubstrate 102. As another form, a component (referred to below as[peeling layer]) which can be peeled may also be provided between thefirst barrier layer 122 and the support substrate 116. The structure ofthis peeling layer is described herein.

The first substrate 102 which forms the display device 100 is preferredto include translucency with a transparency ratio in the visible lightband (wavelength of 400 nan-meters to 800 nanometers) of 80% or more andmore preferably 90% or more. In order to achieve this, the resin layer120 provided above the support substrate 120 is formed using a resinmaterial that can obtain the optical characteristics described above. Itis preferred that a resin material selected from polybenzoxazole,polyamidimide including an alicyclic structure, polyimide including analicyclic structure, polyamide and polyxylylene be used as the resinmaterial and these resin materials may be include independently or aplurality of these resin may be combined.

The thickness of the resin layer 120 is for example 1 micrometer or moreand 100 micrometers or less, preferably 3 micrometers or more and 30micrometers or less and more preferably 5 micrometers or more and 15micrometers or less. By adopting this type of thickness, it is possibleto provide flexibility as wee; as mechanical strength to the firstsubstrate 102.

FIG. 3B shows the step of forming the first substrate 101 by removing apart of the resin layer 120. This stage can also be referred to as astep of forming the outer periphery side surface of the first substrate102 into a taper shape.

Although there is no limitation to the processing method for removingunnecessary parts of the resin layer 120, for example it is possible touse a laser processing technology. In order to selectively process theresin layer 120 it is preferable to use an infrared laser, for exampleit is possible to use a LD pumped solid-state laser with a thirdharmonic wave (355 nanometers).

In order to process the outer periphery side surface of the firstsubstrate 102 and obtain an end surface with a taper shape, it issufficient to appropriately adjust the irradiation strength and beamprofile of the laser beam which is irradiated when processing. Forexample, the energy of the beam spot may be set as a gauss distribution,setting the energy density at the center part high and the energydensity at the periphery parts low in order to remove the resin layer120. In addition, a laser beam with different beam intensities may beirradiated multiple times in order to control the thickness of the resinlayer which is processed.

In either case, the outer periphery side surface of the first substrate102 is preferred to be processed in order to obtain a taper shape inwhich the thickness increases gradually towards the inner side from theouter end. The angle of this taper shape is 60 degrees or less,preferably 45 degrees or less and more preferably 30 degrees or lessusing the surface of the support substrate 116 as a reference. Inaddition, the taper surface at the outer periphery side surface of thefirst substrate 102 may also have a curved surface shape.

FIG. 3C shows the step of forming a second barrier layer 124. The secondbarrier layer 124 is provided so as to cover the upper surface part andouter periphery side surface of the first substrate 102. The secondbarrier layer 124 is preferred to be provided so as to adhere to thefirst barrier layer 122 exposed by removing the resin layer 120. Thatis, the second barrier layer 124 is preferred to be providedcontinuously from the upper surface part and outer periphery sidesurface of the first substrate 102 to the upper surface part of thefirst barrier layer 122. Furthermore, the second barrier layer 124 maybe formed in the same way as the first barrier layer 122.

In this case, it is possible to sufficiently cover the end part of thefirst substrate 102 with the second barrier layer 124 by making theouter periphery side surface of the first substrate 102 into a tapershape. In the case where the outer periphery side surface of the firstsubstrate 102 is a perpendicular surface, it is not possible tosufficiently cover that perpendicular surface using the second barrier124. That is, the film thickness of a barrier layer at the perpendicularend surface of the first substrate 102 is thin, a pin hole is formed andthe barrier properties are lost when cracks appear. However, by makingthe outer periphery side surface of the first substrate 102 into a tapershape, it is possible to for the second barrier layer 124 to cover thisend surface and maintain the barrier properties with respect to waterand oxygen.

In the processes up to FIG. 3C, it is possible to obtain a form wherebythe lower layer side, upper layer side and outer periphery side surfaceof the first substrate 102 is enclosed by a barrier layer. In addition,in the region in which the resin layer 120 is removed, it is possible toarrange a part in which the second barrier layer 124 and first barrierlayer 122 are adhered to the outer end part of the first substrate 102when removing the first substrate 102 from the support substrate andextracting a display panel by adopting a structure in which the secondbarrier layer 124 and first barrier layer 122 are adhered. In this way,the end surface region of the first substrate 102 becomes sealed and itis possible to prevent water or oxygen from entering.

FIG. 3D shows a structure in which a first device layer 130 including acircuit device such as a transistor and a second device layer 132including an organic EL device etc. are formed above the first substrate102 formed with second barrier layer 124. In the present embodiment,there is no particular limitation to the structure of the first devicelayer 130 and the second device layer 132. For example, a wiring layeror an interlayer dielectric provided between wires may also be includedin the first device layer 130 including a semiconductor layer formedwith a transistor, a gate insulating layer and gate electrode layer etc.In addition, an organic EL layer which forms an organic EL device, anelectrode layer sandwiching the organic EL layer, and a bank layer whichencloses the organic EL device may also be included in the second devicelayer 132.

A passivation layer 136 may also be provided on an upper layer of thesecond device layer 132. The passivation layer 136 is the same as thefirst barrier layer or second barrier layer and is preferred to beformed using silicon nitride for example.

The passivation layer 136 covers the side surface part from the uppersurface part of the second device layer 132 and the side surface part ofthe first device layer and is preferred to be provided so that the outerside region is in close contact with second barrier layer 124. In thiscase, the end part of the first device layer 130 is preferred to belocated in a region further to the interior than the outer peripheryside surface of the first substrate 102 and the end part of the seconddevice layer 132 is preferred be located further to the interior than anend part of the first device layer 130 forming a step structure. Inaddition, the side surface parts of the first device layer 130 and thesecond device layer 132 are preferred to slant in a taper shape in eachlayer. By adopting this form, the side surface parts of the first devicelayer 130 and the second device layer 132 can be sufficiently covered bythe passivation layer 136.

FIG. 3D shows the state in which the second substrate 104 is providedfacing the first substrate 102 and is fixed by a sealing material. Thesecond substrate 104 is formed using a resin material the same as thefirst substrate 102 and a third barrier layer 126 is provided over thesurface of the second substrate 104. In FIG. 3D, the second substrate104 is in a state supported by a second support substrate 118 and afiller material 140 may be filled into an interval part formed using asealing material 138. The filler material 140 is an arbitrary componentand a resin for example may be used.

FIG. 4A shows a state in which a polarization plate 142 is providedafter peeling the second substrate 104 from the second support substrate118. A circular polarization plate is used as the polarization plate 142and using this it is possible to prevent a display surface becoming amirror and reflecting an external appearance. Furthermore, thepolarization plate 142 is arbitrary and may or may not be providedappropriately.

As is shown in FIG. 4B, the first barrier layer 122, second barrierlayer 124 and passivation layer may be removed at the outer peripherypart of the first substrate 102 in an outer side region of the firstsubstrate 102 before peeling the first substrate 102 from the supportsubstrate 116. By arranging in advance a separated region where thefirst barrier layer 122, second barrier layer 124 and passivation layer136 are removed, these layers remain as barriers when the firstsubstrate 102 is separated from the support substrate 116 and it ispossible to prevent damage to the layers and a reduction in barrierproperties of the end part region. Furthermore, it is preferred that aregion remains where at least the first barrier layer 122 and secondbarrier layer 124 overlap in the outer side of the first substrate 102.Furthermore, removal of the first barrier layer 122, second barrierlayer 124 and passivation layer 136 may be performed using a laserprocess for example.

FIG. 4C shows a stage where the first substrate 102 is separated fromthe support substrate 116 (essentially, separated from the lower surfaceof the first barrier layer 122). In this way, the first substrate 102becomes free from the support substrate 116 and it is possible obtain asheet shaped display device. Furthermore, a thermal diffusion sheet mayalso be provided over the first substrate 102 side.

It is possible to use a number of methods in order to separate the firstsubstrate 102 from the support substrate 116. An example of thesemethods is explained while referring to FIG. 5A-5C. All of the examplesshown in FIG. 5A-5C show a method of arranging a peeling layer 134between the support substrate 116 and the first barrier layer 122 andthe first substrate 102 is separated from the support substrate 116using the peeling layer 134.

FIG. 5A shows an example where a resin material is used as the peelinglayer 134. The resin layer comprised from a resin material is providedin advance between the support substrate 116 and the first barrier layer122. For example, polyimide may be used as the resin material. Thepeeling layer 134 comprised from polyimide can be formed by coating asolution containing polyamic acid (one part including an imide modifiedpolyamic acid) which is a polyimide precursor, or soluble polyimideabove the support substrate 116 and sintering.

In order to perform peeling, an infrared light beam is irradiated fromthe support substrate 116 side which is a glass substrate and theadhesion at the boundary between the peeling layer 134 which is a resinmaterial and the support substrate 116 is reduced. That is, when aninfrared light beam is irradiated, the bond between polyimide and glassis broken and by partially removing the organic component, the adhesivestrength of the peeling layer is reduced. Using this property it ispossible to separate the first substrate 102 from the support substrate116. According to this method, because the peeling layer 134 is also aresin material the same as the first substrate 102, the consistency ofthe manufacturing process is high.

FIG. 5B shows an example of using an amorphous thin film includinghydrogen as the peeling layer 134. It is possible to use a hydrogenatedamorphous silicon film for example as the amorphous thin film includinghydrogen. A hydrogenated amorphous silicon film is formed in advance asthe peeling layer 134 between the support substrate 116 and the firstbarrier layer 122, a laser beam is irradiated onto the hydrogenatedamorphous silicon film in the peeling process and instantly heated. Alarge amount of hydrogen is instantly released from the hydrogenatedamorphous silicon film by heating, and due to an accompanying rise inpressure and change in the hydrogenated amorphous silicon film, theadhesion between the support substrate 116 or the first barrier layer122 is reduced and it is possible to separate the first substrate 102from the support substrate 116. It is possible to form the hydrogenatedamorphous silicon film on a large area using a film formation methodsuch as plasma CVD method and because the film formation is simple it ispossible to form the peeling layer relatively easily.

FIG. 5C shows an example of using a metal film as the peeling layer 134.In this method, thermal stress is applied between a metal film providedas the peeling layer 134 and the first barrier layer 122 formed from adifferent material, stress is applied due to the difference in stressand peeling is performed. That is, peeling is performed by applyingstress to a boundary of stacked layers having different materials withdifferent thermal characteristics.

In either case, by providing the first barrier layer 122 when separatingthe first substrate 102 from the support substrate 116, it is possibleto prevent damage to the first substrate 102. The peeling method shownin FIG. 5A˜FIG. 5C can also be applied when peeling the second substrate104 from the support substrate 118 in FIG. 4A.

As explained while referring to FIG. 2, FIG. 3A˜FIG. 3D and FIG. 4A˜FIG.4C, according to the present embodiment, it is possible to obtain adisplay device using a simple process using the first substrate 102 andsecond substrate 104 which are formed from a resin material as amaterial. Since the first substrate 102 and second substrate 104 areeither 100 micrometers or less, a sheet shaped display or flexibledisplay can be realized.

It is possible to prevent water or oxygen in the air from entering thefirst substrate 102 by enclosing the upper layer side, lower layer sideand outer periphery side surface taper surface of the first substrate102 with a barrier layer. In this way, it is possible to prevent wateror oxygen from dispersing to the first device layer including atransistor or the second device layer including an organic EL device,prevent corrosion of wiring or electrodes and prevent deterioration ofan organic EL device.

By removing corrosion or deterioration as described above, it ispossible to prevent point defects or line defects in a display screen ofa display device, prevent variation in light emitting brightness andimprove reliability.

<Details of the Display Device>

The details of the display device in the present embodiment areexplained using FIG. 6 and FIG. 7. FIG. 6 shows the structure of aperiphery part in the display device 100 and FIG. 7 shows the structureof an organic EL device 146 in a pixel 106 and a transistor 144connected to the organic EL device 146. Both FIG. 6 and FIG. 7 arereferred to in the explanation below.

The structure of the taper shape at the end part of the first substrate102, and the structure of the barrier layer 122 over the lower layerside (lower surface side), and the structure of the second barrier layer124 which covers the upper layer side (upper surface side) and the tapersurface are the same as the explanation in FIG. 3C.

The first device layer 130 is provided above the second barrier layer124. The device layer 130 is formed including a plurality of layers sothat a transistor 144 is formed. The transistor 144 is formed includinga semiconductor layer 148, a gate insulating layer 150 and a gateelectrode 152. The gate insulating layer 150 which is provided betweenthe semiconductor layer 148 and gate electrode 152 is provided above thefirst barrier layer 122 from the upper surface of the semiconductorlayer 148 extending to the end surface region 105 of the first substrate102 and the second barrier layer 124 is stacked at the taper surface.Since the gate insulating layer 150 is formed using a silicon oxide filmand silicon oxynitride film, the film thickness of the barrier layer isessentially increased by stacking with the second barrier layer 124 atthe taper surface.

Furthermore, although a top gate type structure is shown in FIG. 7 asthe transistor 144, in the case of a bottom gate type structure, thestacking order of the semiconductor 148, gate insulating layer 150 andgate electrode 152 is reversed. However, there is no difference in thestructure of the gate insulating layer 150 at the end surface region105.

A first interlayer dielectric 156 is provided between the gate electrode152 and a source/drain electrode 154 (in the present embodiment,[source/drain electrode] refers to an electrode connected with thesource or drain of a transistor). The first interlayer dielectric 156 isalso preferred to be provided extending to the end surface region 105the same as the gate insulating layer 150 in the case where it is formedusing an inorganic insulating material such as silicon oxide and isstacked with the second barrier layer 124. By stacking with the secondbarrier layer 124 at the taper surface of the end surface region 105, itis possible to essentially increase the film thickness of the barrierlayer. The second interlayer dielectric 158 provided on an upper layerof the source/drain electrode 154 is preferred to be formed using aresin material such as polyimide or acrylic. Apart from the secondinterlayer dielectric 158 insulating an interlayer, the secondinterlayer dielectric 158 is provided with a thickness of 1 micro-meterto 5 micro-meters in order to perform planarization.

Furthermore, neither the gate insulating layer 150 and first interlayerdielectric 156 stacked with the second barrier layer 124 are required tobe stacked, it is sufficient that at least one of the insulating layersis stacked.

In this way, a plurality of layers is included in the first device layer130 and the transistor 144 is formed by this plurality of layers. Inaddition, a part of the layers included in the first device layer 130 isextends to the end surface region of the first substrate 102 and ispreferred to be stacked with the second barrier layer 124.

The second device layer 132 is provided above the first device layer130. An organic EL device 146 is included in the second device layer132. The organic EL layer 146 includes a structure in which a pixelelectrode 162, organic EL layer 164 and opposing electrode 166 arestacked. The pixel electrode 162 is provided in the second interlayerdielectric 158 and is connected to a source/drain electrode 154 of thetransistor 144 via a contact hole. The end part of the pixel electrode162 is covered by a bank layer 168 and the organic EL layer 164 isprovided along the surface of the pixel electrode 162 and bank layer168. The bank layer 168 is provided including a thickness of about 1micro-meter to 3 micro-meters in order to prevent the organic EL device146 shorting due to the step of the pixel electrode 162.

The organic EL layer 164 can be formed using a low molecular or highmolecular organic material. In the case where a low molecular organicmaterial is used for the organic EL layer 164, in addition to a lightemitting layer which includes an organic material with light emittingproperties, a carrier layer such as a hole transport layer or anelectron transport layer may be provided to sandwich the light emittinglayer. In addition, the organic EL layer 164 may emit light of each ofthe colors red (R), green (G) and blue (B), or emit white color light.In the case where the organic EL layer 164 emits white color light, itis possible to combine the organic EL layer 164 with a color filter andperform color display.

The opposing electrode 166 is an electrode common to a plurality ofpixels and is provided on an upper layer of the organic EL layer 164.The opposing electrode 166 extends above the bank layer 166 and isconnected to a common wire 160 which applies a common voltage on theouter side of the pixel region 108. FIG. 6 shows the case where thecommon wire 160 is formed on the same layer as the gate electrode 152and shows the form where the common wire 160 and the opposing electrode166 are connected via a contact hole which passes through the bank layer168, second interlayer dielectric 158 and first interlayer dielectric156.

The passivation layer 136 is provided to roughly cover the entiresurface of the first substrate 102 over the upper layer side of theopposing electrode 166. The end surface region 105 of the firstsubstrate 102 is also preferred to be covered by the passivation layer136 and the end part taper surface is stacked with the secondpassivation layer 124, gate insulating layer 150, first interlayerdielectric 156 and passivation layer 136. Using the structure, it ispossible to improve the barrier properties of the first substrate 102.

In this case, the end part of the second interlayer dielectric 158 islocated further to the interior than the end surface region 105 of thefirst substrate 102 and the side surface part (end part) is alsopreferred to have a taper shape. In addition, the end part of the banklayer 168 is preferred to be located further to the interior than theend part of the second interlayer dielectric 158 and the end part ispreferred to have a tape shape. The passivation layer 136 covers theside surface from the upper surface of the bank layer 168 and the sidesurface of the second interlayer dielectric and can be provided so as tocover the end surface region 105 of the first substrate 102. At thistime, when the side surface part of the second interlayer dielectric 158and the side surface part of the bank layer 168 are tapered surfaces andnot perpendicular surfaces, it is possible to improve the coverproperties of the passivation layer 136. In addition, by making the stepformed by the second interlayer dielectric 158 and bank layer 168provided to a thickness of a few micro-meters as described above into astep shape, it is possible to improve the cover properties of thepassivation layer 136.

The second substrate is provided facing the first substrate 102 and isfixed by a sheet material 138. A third barrier layer 126 is providedover the surface of the second substrate 104 and a color filter 172 orovercoat layer 174 may be provided in the pixel region 108.

According to the present embodiment, by adopting this type of structureit is possible to enclose not only the first substrate 102 but also thesecond interlayer dielectric 159 formed from a resin material and thebank layer 168 using a cover layer formed from an inorganic material. Inthis way, it is possible to block each layer formed from a resinmaterial forming the display device 100 from being exposed to the airand prevent water (water vapor) or oxygen in the air from entering theinside of a display panel, prevent corrosion of wiring or electrodes andprevent deterioration of the organic EL device 146.

Furthermore, in the present invention, the display device which uses anorganic EL device may be a bottom emission type which irradiates lightto the first substrate side or a top emission type which irradiateslight to the opposing substrate side.

In addition, the present invention is not limited to a display device.The organic EL device can be provided on roughly one surface between thefirst substrate and second substrate and can also be applied to alighting device.

Furthermore, although the case where an organic EL device is used as adisplay device is shown in the present embodiment, the present inventionis not limited to an organic EL device and the same effects can beobtained by using a liquid crystal device as the display device. Theliquid crystal device includes a structure in which a liquid crystallayer is inserted between a pixel electrode and an opposing electrode.In the present embodiment, it is possible to obtain a liquid crystaldisplay device by adopting a structure in which a liquid crystal layeris provided above the pixel electrode 162 and sandwiching this lightcrystal layer using the second substrate 104 provided with an opposingsubstrate. An orientation layer which defines the orientation of theliquid crystals or a color filter in the second substrate 104 may alsobe appropriately provided. In the case where the structure of thebarrier layer in the present embodiment is applied to a liquid crystaldisplay device, moisture resistance of the first substrate 102 andsecond substrate 104 can be improved and reliability can be improved.

Second Embodiment

The structure of the display device related to one embodiment of thepresent invention is shown in FIG. 8. Since the structure of the displaydevice shown in FIG. 8 is the same as the first embodiment apart fromthe second substrate 104, only the parts which are different areexplained.

In FIG. 8, the end part of the second substrate 104 has a taper shapethe same as the first substrate 102. The third barrier layer 126 isprovided so as to cover the surface and side surface of the secondsubstrate 104. By adopting this structure, it is possible to cover theside surface part of the second substrate 104 using the third barrierlayer 126 and prevent water from entering from the side surface part.

Since the structure of the first substrate 102 is the same as in thefirst embodiment it has the same effects as in the first embodiment andbecause a path blocking water from entering from the outer can befurther obtained according to the present embodiment it is possible tofurther increase reliability of the display device.

Third Embodiment

The structure of the display device related to one embodiment of thepresent invention is shown in FIG. 9. Apart from the structure of thefirst embodiment 102 being different, since the structure of the displaydevice shown in FIG. 9 is the same as the structure described in thefirst and second embodiments, only the parts which are different areexplained.

In FIG. 9, a fourth barrier layer 128 is provided between the firstsubstrate 102 and the second barrier layer 124. While the first barrierlayer 122 is provided using an inorganic material, the fourth barrierlayer 128 is formed using a metal material. A cover film using a metalmaterial can be suitably applied as a barrier layer since it has highwater blocking properties. Although it is possible to use various metalmaterials, it is preferred that titanium (Ti) for example is used.

It is possible to increase barrier properties by stacking a plurality oflayers comprised from different materials which have high barrierproperties with respect to water as the barrier layer with respect tothe first substrate 102.

In the case where the first barrier layer 122 is an inorganic insulationfilm such as silicon oxide or silicon nitride, while this inorganicinsulation film is formed using a plasma CVD method, the metal filmusing titanium (Ti) can be formed using a sputtering method. In thisway, by forming a barrier layer by combining a chemical vapor depositionmethod (CVD) which uses a chemical reaction and a physical vapordeposition method (PVD) which uses physical work such as sputtering,because it is possible to form a cover film on parts of one film whichhave pinholes even if pinholes are produced in the other film andeliminate the effects of defects, it is possible to improve the barrierproperties of a barrier layer.

In addition, by arranging the fourth barrier layer 128 which is formedfrom a metal material on a lower layer of the first barrier layer 122which is formed from an insulating material, because it is possible towiden the distance with a wiring layer included in the first devicelayer 130, it is possible to reduce the effects of parasiticcapacitance.

In this way, apart from the fourth barrier layer 128, because it ispossible to apply the structure of the first and second embodiments, itis possible to obtain the same effects and by adding a layer formed froma metal material as a barrier layer according to the present embodiment,it is possible to further improve the barrier properties against wateror oxygen with respect to the first substrate 102.

Furthermore, the structure of the fourth barrier layer 128 shown in FIG.9 may also be provided with respect to the second substrate 104. In thisway, it is possible to further increase barrier properties in the secondsubstrate 104.

What is claimed is:
 1. A display device comprising: a first substratecomprising a resin material provided with a plurality region providedwith a plurality of pixels including a display device; a secondsubstrate provided facing the first substrate and installed with thepixel region; and an outer periphery side surface of the first substratehaving a taper shape and including a barrier layer covering an upperlayer, lower layer and the outer periphery side surface of the firstsubstrate.
 2. The display device according to claim 1, wherein thebarrier layer comprises a first barrier layer provided on a lower layerof the first substrate and a second barrier layer provided on an upperlayer of the first substrate; and the second barrier layer is providedalong the outer periphery side surface from an upper surface of thefirst substrate and contacts the first barrier layer in an outer sideregion of the first substrate.
 3. The display device according to claim1, wherein the barrier layer comprises an inorganic material.
 4. Thedisplay device according to claim 3, wherein the inorganic material isselected from the group consisting of silicon nitride, silicon oxide,silicon oxynitrde and aluminum oxide.
 5. The display device according toclaim 1, wherein a third barrier layer comprising of metal material isfurther provided between the first substrate and the second barrierlayer.
 6. The display device according to claim 5, wherein the firstbarrier layer and the second barrier layer is contacting in an outerside region of the third barrier layer.
 7. The display device accordingto claim 4, wherein the metal material is titanium.
 8. The displaydevice according to claim 1, wherein the second substrate is formed froma resin material, an outer periphery side surface of the secondsubstrate having a taper shape, and a fourth barrier layer is includedon a surface facing the outer periphery side surface and the firstsubstrate.
 9. The display device according to claim 1, wherein apassivation layer is included to cover the pixel region, the passivationlayer is provided extending as far as the outer periphery side surfaceof the first substrate and overlaps the barrier layer in the outerperiphery side surface.
 10. The display device according to claim 1,wherein the pixel region comprises a transistor, the transistor includesa semiconductor layer forming a channel, a gate electrode and a gateinsulating layer between the semiconductor layer and gate electrode; asource-drain electrode is contacting a source or drain of the transistorvia a first interlayer dielectric is provided on an upper layer of thegate electrode; and either one or both of the gate insulating layer andfirst interlayer dielectric is provided extending as far the outerperiphery side surface of the first substrate and overlaps the barrierlayer in the outer periphery side surface.
 11. The display deviceaccording to claim 9, wherein a second interlayer dielectric, a pixelelectrode above the second interlayer dielectric, an organicelectroluminescence device stacked with an organic electroluminescencelayer and opposing electrode, a bank layer covering an end part of thepixel electrode, and a bank layer above the opposing electrode areprovided on an upper layer of the first interlayer dielectric; and thepassivation layer is extending to the outer periphery side surface ofthe first substrate, and the passivation layer, the gate insulatinglayer, the interlayer dielectric and the barrier layer are stacked inthe outer periphery side surface of the first substrate.
 12. The displaydevice according to claim 11, wherein a part of the second interlayerdielectric and the bank layer includes a taper shape, and thepassivation layer is provided along the end part of the bank layerextending as far as the outer periphery side surface of the firstsubstrate.
 13. The display device according to claim 12, wherein the endpart of the second interlayer dielectric is provided further to theinterior than the outer periphery side surface of the first substrate,and the end part of the bank layer is provided further to the interiorthan the end part of the second interlayer dielectric.
 14. The displaydevice according to claim 11, wherein a stacked layer of the passivationlayer, the gate insulating layer, the interlayer dielectric and the banklayer is extends to the outer periphery side surface of the firstsubstrate.
 15. The display device according to claim 1, wherein thedisplay device is an organic electroluminescence device or liquidcrystal device.